反应详情

A mixture of 300 ml of carbon disulphide, 80 g (0.60 mol) of powdered aluminium trichloride and 28.9 g (0.20 mol) of 2-chloro-1,2-benzenediol is stirred for 15 minutes at room temperature and then for 1 hour at 40°. 30.9 g (0.220 mol) of benzoyl chloride are then added over a period of 10 minutes and the whole is stirred for a further 15 minutes at 40° and heated in order slowly to distil off the carbon disulphide. The dry residue is then heated to 140° (bath temperature) in the course of 1 hour and maintained at this temperature for 31/2 hours. The brown solid mass is cooled, 300 ml of 3N hydrochloric acid and 200 ml of ethyl acetate are added and the mixture is stirred until completely dissolved. The organic phase is separated off and the aqueous phase is extracted with ethyl acetate. The combined organic phases are washed with water and saturated sodium chloride solution, dried over sodium sulphate, treated with carbon and concentrated by evaporation. The dark-brown residue is dissolved in 100 ml of 1,2-dichloroethane, 105 ml of n-hexane are added and the whole is triturated until crystallisation takes place. The crystals are filtered with suction and recrystallised from dichloroethane/hexane. The (2-chloro-4,5-dihydroxyphenyl)-phenylmethanone, obtained in the form of white crystals (melting point 130°-135°), can be further reacted directly.

1. waitfor 1 hour at 40°
2. stirringthe whole is stirred for a further 15 minutes at 40°
3. temperatureheated in order slowly
4. customto distil off the carbon disulphide
5. temperatureThe dry residue is then heated to 140° (bath temperature) in the course of 1 hour
6. temperaturemaintained at this temperature for 31/2 hours
7. temperatureThe brown solid mass is cooled
8. addition300 ml of 3N hydrochloric acid and 200 ml of ethyl acetate are added
9. stirringthe mixture is stirred
10. dissolutionuntil completely dissolved
11. customThe organic phase is separated off
12. extractionthe aqueous phase is extracted with ethyl acetate
13. washThe combined organic phases are washed with water and saturated sodium chloride solution
14. dry with materialdried over sodium sulphate
15. additiontreated with carbon
16. concentrationconcentrated by evaporation
17. dissolutionThe dark-brown residue is dissolved in 100 ml of 1,2-dichloroethane
18. addition105 ml of n-hexane are added
19. customthe whole is triturated until crystallisation
20. filtrationThe crystals are filtered with suction
21. customrecrystallised from dichloroethane/hexane